Efficient direct shoot organogenesis from seedling derived split node explants of maize ( L.).

Maize is one of the important cereal crops around the world. An efficient and reproducible regeneration protocol direct organogenesis has been established using split nodes as ex-plants derived from 7 to 10 day old grown seedlings. Surface sterilized maize seeds were germinated on MS medium lacking plant growth regulators. Nodal sections of 7-10 day old seedlings were isolated, split longitudinally into two halves and cultured on regeneration medium containing different concentrations of 6-benzyladenine (2.20, 4.40, 6.60, 8.80, 11.0 and 13.2 μM) or kinetin (2.32, 4.65, 6.97, 9.29, 11.6 and 13.9 μM). Inclusion of 8.80 μM BA into MS supplemented medium triggered a high frequency of regeneration response from split node explants with a maximum number of shoots (12.0 ± 1.15) and the highest shoot length (3.0 ± 0.73) was obtained directly (without an intervening callus phase) within 4 weeks of culture. Further shoot elongation was achieved on medium containing 4.40 μM BA. The elongated micro shoots were rooted on MS medium fortified with 1.97 μM indole-3-butyric acid. The regenerated plantlets with roots were successfully hardened on earthen pots after proper acclimatization under greenhouse conditions. This new efficient regeneration method provides a solid foundation for genetic manipulation of maize for biotic and abiotic stresses and to enhance the nutritional values.